I use windows 7 (64bit) currently but I wonder what would be the most effective way to switch to ubuntu for the web surfing (youtube mostly)?
Should I dual boot? (ugh but the restarts)

What about virtual space?(how much does virtual space suffer in speed)

should I keep windows 7 as the main and then use virtual for Ubuntu or Ubuntu (main) and windows (virtual)?

Some little facts: Im almost a total newbie to practical computer use but not to theory so I should understand most lingo.
I plan on building a PC with a higher end i7 processor to lessen the effects of question 1.

3 Answers
3

1: we can not correctly answer this. It is not only affected by your system but also by the amount of resources you will make available for the VM. A VM will cut down your resources but how much you will need to find out the hard way. Then there is the game itself. Some games work very will with a VM others are impossible to play. In general it is best to stick with the main OS for games. Games are resource hungry anyways.

2: So as explained with 1: My advice would be Windows with Ubuntu in VM. Games run better on the main OS. VM's will always cut into your resources.

A possible setup for trial purposes would be to install an OS and then install both Windows and Ubuntu and try if you can find a sweet spot where games run as good as you want in either of the VMs or if the main OS still is the best option.

The best security is done with a router (if talking about people trying getting access to your machine) and not with your OS so what OS is main and what OS is in a VM does not really matter then. Secondly comes common sense: do not visit shady websites (when talking about virusses and malicious programs).

Depending on the games you might also be able to use Ubuntu with wine. I play Guild Wars 2 using Ubuntu+wine. No guarantee all games work and most times it is a bit of work to get it working well but it might be an option.
In my own experience GW2 is about 10, 20% less good than when I play it on a Windows system. But this is not speed related but graphics related (graphics are a bit less).

You can install Ubuntu using Virtualbox. It's a software used to emulate operating systems. With Virtualbox you'll be able to use Ubuntu (and other operating systems) without restarting your computer. You can download it here https://www.virtualbox.org/wiki/Downloads

If you really like Ubuntu I suggest you to install it along side with Windows (dual boot). This way you'll have the best experience with Ubuntu. Virtualbox is nice but it's a little limited. But should be enough for you to try and use it for browsing the internet.